Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 351 PM EDT Thu Jul 12 2018 Valid 00Z Fri Jul 13 2018 - 00Z Sun Jul 15 2018 ...Severe thunderstorms and flash flooding expected across portions of the Northern Plains and Upper Mississippi Valley through Friday... ...Heavy rainfall and flash flooding possible across portions of the Southwest and southern Rockies... ...Showers and thunderstorms will be present across the Mid-Atlantic and and portions of the Southeast and Gulf States into this weekend... ...Post-Tropical Cyclone Chris will continue to track northeast into the northern Atlantic Ocean... A slow moving cold front will lead to the development of showers and thunderstorms across portions of the Northern Plains and Upper Missippi Valley starting late this afternoon and continuing overnight. Another round of showers and thunderstorms is expected for late Friday afternoon and Friday night as well. Any thunderstorms that develop are anticipated to be slow moving, and could result in large amounts of rainfall on top of already saturated soils. As a result, a flash flood watch has been issued for portions of southeast South Dakota, southwest Minnesota, and far northwest Iowa. The Storm Predicition Center also has outlined this area within a slight risk of severe thunderstorm development for today and tonight. South of this slow moving frontal system, a surge of warm, moist air has made its way from the Gulf of Mexico and across much of the central United States. This has led to excessively hot and humid conditions that are expected to persist through Friday. Heat advisories are in place across much of the eastern Plains and western and northern Missisippi Valley for today through Friday. Widespread convection will continue across much of the Desert Southwest and Southern Rockies as monsoonal moisture advects northward. Heavy rainfall along the terrain could lead to flash flooding, with a magnified threat in flood prone areas. WPC has a majority of this region in a marginal to slight risk for excessive rainfall and flash flooding through Saturday. Scattered to numerous showers and thunderstorms will be present across the Mid-Atlantic and portions of the Southeast and Gulf states into the weekend. A frontal boundary will slowly drift southward and act as a focus for convection. Abundant moisture feeding into this region along will slow sell motion, heavy rainfall may be possible - especially for the Carolinas and Georgia. WPC has identified this area as having a marginal risk for excessive rainfall. Hurricane Chris has been downgraded to a Post-Tropical Cyclone and continues to travel northeast into the northern Atlantic. Expect this system to pass just south of Newfoundland over the coming day, but should no longer pose a threat to the continental United States. For the latest position and impacts, visit the National Hurricane Center (www.hurricanes.gov). Wix Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php